Method and apparatus for exercising

Abstract

An exercising method and apparatus for use in the treatment of paralyzed muscles. The method and apparatus make use of a set of transcutaneous electrodes which are placed upon the skin of the subject over muscles which are to be stimulated. A computer controlled stimulator generates a pair of alternately pulsed stimulation signals which are applied across different pairs of stimulation electrodes to produce controlled muscle contraction. Muscle movement is resisted by a dynamic load, and a position sensor provides a feedback signal indicating the movement actually achieved. The computer uses the feedback signal for modifying the control signal applied to the stimulator. The exercise routine is disclosed as being conducted upon the leg of a subject seated in a specially designed exercise chair.

What is claimed is: 
     
       1. Method of exercising a human muscle comprising the steps of: (1) attaching a plurality of transcutaneous stimulators to the skin of said human in a pattern above said muscle,   (2) applying to said stimulators a plurality of stimulation signals having profiles for causing said muscle to contract and produce movement of a limb connected thereto,   (3) applying a resisting force to said limb for causing exertion of said muscle during said movement,   (4) sensing said movement and generating a feedback signal corresponding thereto,   (5) monitoring said feedback signal to determine when a predetermined response has been achieved,   (6) after said predetermined response has been achieved, altering said stimulation and permitting said muscle to relax, and   (7) repeating aforesaid steps to produce an exercise routine.   
     
     
       2. Exercising method comprising the steps of: (1) attaching a plurality of transcutaneous stimulation electrodes to an area of skin in a pattern for selectively stimulating at least one muscle thereunder,   (2) restraining movement of a limb connected for movement by said muscle,   (3) applying a series of increasingly severe isometric stimulation signals to said stimulation electrodes,   (4) measuring the movement force developed by said limb during stimulation by said isometric stimulation signals,   (5) recording the maximum straining force developed by said limb during isometric stimulation thereof,   (6) discontinuing said isometric stimulation signals,   (7) freeing said limb for movement,   (8) applying a series of dynamic stimulation signals to said stimulation electrodes for initiating movement of said limb,   (9) applying against said limb a movement resisting force having a magnitude which is a predetermined fraction of said maximum straining force,   (10) sensing movement of said limb and generating a feedback signal corresponding thereto,   (11) adjusting said stimulation signals in response to said feedback signal for controlling the motion of said limb in a predetermined manner,   (12) interrupting said dynamic stimulation signals to permit said muscle to relax, and   (13) repeating aforesaid steps 8-12 to produce an exercise sequence.   
     
     
       3. Method according to claim 2 and further comprising the step of discontinuing said exercise routine when said feedback signal causes said dynamic stimulation signals to reach a level indicating muscle fatigue. 
     
     
       4. Method according to claim 3 and further comprising the steps of recording the isometric stimulation signal level which first produces muscular response and setting the initial value of said dynamic stimulation signals equal to said isometric stimulation signal level. 
     
     
       5. Method according to any of claims 1-4 wherein said stimulation signals are pulsed. 
     
     
       6. Method according to claim 5 wherein said stimulation signals are applied across said electrodes in two pairs; the signal across each said electrode pair being pulsed at frequency between about 55 and 65 Hz and the pulses across different electrode pairs being alternated. 
     
     
       7. Method according to claim 6 wherein said pulses have a duration of about 500 microseconds. 
     
     
       8. Apparatus for exercising a paralyzed leg comprising: a chair including a seat,   a leg strap retained below said seat for grasping said leg,   cable means for connection to said strap,   load means for applying a leg restraining tension to said cable means,   feedback means for generating a feedback signal corresponding to movement of said cable means, and   stimulation means responsive to said feedback signal for stimulating normally paralyzed muscles within said leg to cause coordinated movement thereof against the restraining action of said load means.   
     
     
       9. Apparatus according to claim 8 and further comprising releasible restraining means for restraining movement of said strap and force indicating means for providing an indication of the force exerted by said leg against said strap when said muscle is stimulated and said strap is restrained as aforesaid. 
     
     
       10. Apparatus according to claim 8 wherein said load means comprises vertical support means for suspending a plurality of selected weights and means for transmitting the combined weight force of said weights into said cable means. 
     
     
       11. Apparatus according to claim 10 wherein said feedback means comprises a potentiometer mounted for activation by movement of said cable means. 
     
     
       12. Apparatus according to any of claims 8-11 wherein said chair is movable relative to said strap for permitting attachment of said strap to either leg of a person seated in said chair.